#arduino

Programming Languages Bug Report

Arduino controller stops after 49.7 days: millis() overflow in interval checks

Daniel Tran · May 26, 2026 · 8 min read

Our dosing controllers ran for weeks, then locked themselves out on day 49. The interval check compared now >= lastRun + interval, which breaks when the sum wraps past 2^32 milliseconds. How we proved it with a simulated clock and fixed it with unsigned subtraction.

Embedded & IoT Bug Report

ESP32 reboots with Brownout detector was triggered as soon as Wi-Fi starts

Daniel Tran · Oct 21, 2025 · 9 min read

Our greenhouse sensor boards boot-looped the moment WiFi.begin() ran, logging Brownout detector was triggered. The 3.3 V rail sagged under Wi-Fi transmit peaks from an undersized LDO and thin cable. How we measured it, fixed the power path and why disabling the detector is the wrong fix.